Cooling problems which occur in piston-type compressors are well known. In particular special heat problems occur in dry-operation compressors wherein the pistons slide on guide and compression rings of large surface area which comprise PTFE (Teflon). Heat acting on the piston from the direction of the piston crown has a negative influence on the anti-friction properties of the piston rings, reduces the service life thereof, and, in the extreme case, results in damage to the piston rings.
Problems with heat also occur in connection with the piston of internal combustion engines and attempts have already been made, at a relatively early date, for satisfactory solutions to such problems.